We've got two numbers: 138 and 602. Let's find their sum.

Step 1: We'll start by adding the digits 8 & 2 in column 1 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 3 & 0 in column 2 and get 4.

Step 3: We'll start by adding the digits 1 & 6 in column 3 and get 7.

So, 138 + 602 = 740.

